In the course of time a step may form, partly due to erosion, between the roadway pavement and the unpaved side strip of a roadway, or the shoulder (herein also referred to as roadway periphery). If the wheels on one side of the vehicle enter the shoulder in such areas, the vehicle often becomes instable when returning it to the roadway, because many drivers try to steer the vehicle onto the roadway applying a large steering angle, and the vehicle follows this steering angle abruptly as soon as it is on the roadway again, or the tire has been damaged and lost air due to an edge formed by the step. There are systems which are intended to prevent unintentionally leaving a lane of a roadway, so-called lane keeping assistants. Such systems can usually be overridden by the driver, however, e.g. to enable avoiding an obstacle, and therefore cannot prevent the vehicle from getting into the situation described above when driving over a step between the roadway and the shoulder. It is exactly for situations like these that assistance to the driver would be desirable, especially to prevent the vehicle being returned from becoming instable when driving over a step between the roadway and the shoulder which is too high.